Messages in this thread | | | Date | Sat, 22 Jan 2022 13:39:30 -0500 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 5.16 02/52] clk: samsung: exynos850: Register clocks early |
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On Mon, Jan 17, 2022 at 09:18:43PM +0200, Sam Protsenko wrote: >On Mon, 17 Jan 2022 at 19:11, Krzysztof Kozlowski ><krzysztof.kozlowski@canonical.com> wrote: >> >> On 17/01/2022 17:58, Sasha Levin wrote: >> > From: Sam Protsenko <semen.protsenko@linaro.org> >> > >> > [ Upstream commit bcda841f9bf2cddcf2f000cba96f2e27f6f2bdbf ] >> > >> > Some clocks must be registered before init calls. For example MCT clock >> > (from CMU_PERI) is needed for MCT timer driver, which is registered >> > with TIMER_OF_DECLARE(). By the time we get to core_initcall() used for >> > clk-exynos850 platform driver init, it's already too late. Inability to >> > get "mct" clock in MCT driver leads to kernel panic, as functions >> > registered with *_OF_DECLARE() can't do deferred calls. MCT timer driver >> > can't be fixed either, as it's acting as a clock source and it's >> > essential to register it in start_kernel() -> time_init(). >> > >> > Let's register CMU_PERI clocks early, using CLK_OF_DECLARE(). CMU_TOP >> > generates clocks needed for CMU_PERI, but it's already registered early. >> > >> > While at it, let's cleanup the code a bit, by extracting everything >> > related to CMU initialization and registration to the separate function. >> > >> > Similar issue was discussed at [1] and addressed in commit 1f7db7bbf031 >> > ("clk: renesas: cpg-mssr: Add early clock support"), as well as in >> > drivers/clk/mediatek/clk-mt2712.c. >> > >> > [1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20180829132954.64862-2-chris.brandt@renesas.com/ >> > >> > Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org> >> > Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> >> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> >> > Link: https://lore.kernel.org/r/20211122144206.23134-1-semen.protsenko@linaro.org >> > Signed-off-by: Sasha Levin <sashal@kernel.org> >> > --- >> > drivers/clk/samsung/clk-exynos850.c | 70 ++++++++++++++++++++--------- >> > 1 file changed, 49 insertions(+), 21 deletions(-) >> > >> >> I propose to skip this one. >> >> Backporting it to v5.16 does not hurt but also does not bring any >> benefits for the upstream kernel users. There is no support for >> mentioned Exynos850 in v5.16. >> >> It could have only meaning for some downstream, out-of-tree kernels >> which apply Exynos850 support on top of v5.16, but then they can just >> take this patch as well. >> > >Agreed. DTS patches will be merged only in v5.17, hopefully. Till that >time the whole clock driver is floating with no users. That's >historical thing -- I didn't have "Ack" to submit board dts at the >time, and SoC dts couldn't be applied without users (board dts). So I >focused on driver work, isolated. Not much sense to backport something >without having real users.
Dropped, thanks!
-- Thanks, Sasha
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